Deactivation of hydroprocessing catalysts

As part of a continuing scientific challenge, a substantial effort during the past few decades has been devoted towards altering the selectivity of chemical transformations by arranging the potential reactants in a number of organized and confining media. Such systems, having features significantly different from those of isotropic solutions, include, for example, micelles, microemulsions, molecular aggregates, liquid crystals, and zeolites. Among these materials, stimuli-response gels constitute another important class of nanostructured and dynamic systems with high active surface areas and remarkable diffusion properties. Within this group, polymer gels have been traditionally used to obtain catalytic and reactive soft materials. Moreover, gels made of low-molecular-weight compounds represent a major novelty in this area as potential soft-vessels to carry out chemical reactions with control on product selectivity. In addition, the possibility of integrating switchable catalytic functions in both organo- and hydrogels shall accelerate the development of robust platforms for the ‘bottom–up’ tailor-fabrication of more sophisticated functional materials. The present critical review reports on the most important results published during the last decade regarding the use of ‘smart’ gels that has displayed promising properties as selective soft-nanoreactors and/or heterogeneous recyclable catalysts (152 references).

Stimuli-responsive gels as reaction vessels and reusable catalysts

An in situ process for treating a hydrocarbon containing formation is provided. The process may include providing heat from one or more heaters to at least a portion of the formation. The heat may be allowed to transfer from the one or more heaters to a part of the formation such that heat from the one or more heat sources pyrolyzes at least some hydrocarbons within the part. Hydrocarbons may be produced from the formation.

In situ recovery from a hydrocarbon containing formation

Soft and flexible hydrogel templates of different sizes and various functionalities for metal nanoparticle preparation and their use in catalysis

A high level of hydrodenitrogenation (HDN) is required to achieve a desirable conversion of other hydroprocessing reactions. This results from a strong adsorption of nitrogen‐containing compounds on catalytic sites that slows down the hydrogen activation process and hinders the adsorption of other reactants. Studies on model compounds and real feeds indicate that less than 50 ppm of nitrogen in the feed can poison catalytic sites. Kinetic studies determined adsorption constants of various nitrogen‐containing compounds and concluded that at least four different catalytic sites are required to interpret experimental observations in contrast with a dual site site≅concept, which only considered two sites. The advancements in experimental techniques allowed identification of products formed during very early stages of hydrodenitrogenation. These results confirmed that the removal of the amino group from saturated amines, as the last step in hydrodenitrogenation, is governed by the type of carbon to which the a...

Hydrodenitrogenation of Petroleum

The invention relates to an improved method of presulfurizing a sulfidable metal oxide(s)-containing catalyst which minimizes sulfur stripping upon start-up of a reactor and improves catalyst activity. The method consists of contacting a sulfidable metal oxide(s)-containing catalyst with elemental sulfur at a temperature such that said elemental sulfur is substantially incorporated in the pores of said catalyst by sublimation and/or melting and heating the sulfur-incorporated catalyst in the presence of a liquid olefinic hydrocarbon at a temperature greater than about 150° C.

Process of hydrotreating and/or hydrocracking hydrocarbon streams or tail gas treating sulfur-containing gas streams

A process is provided for hydrotreating hydrocarbon oils having a tendency to deactivate hydrotreating catalysts by coke formation, said oils selected from the group consisting of (a) oils having a final boiling point greater than about 1000° F. and containing less than about 2% by weight of heptane asphaltenes, (b) oils having a final boiling point from about 650° F. to about 1000° F. and (c) mixtures thereof, which comprises: passing said oils downwardly with a hydrogen-containing gas into a hydrotreating zone over a stacked-bed of two hydrotreating catalysts under conditions suitable to convert greater than about 25% of the sulfur compounds present to H2 S; said stacked bed comprising an upper bed consisting of about 15-85% v, basis total catalyst, of a high-activity hydrotreating catalyst containing from about 2-4% w nickel, from about 8-15% w molybdenum and from about 1-4% w phosphorus supported on a carrier consisting mostly of alumina; and a lower bed consisting of about 15-85% v, basis total catalyst, of a high-activity desulfurization catalyst which contains from about 2-4% w cobalt and/or nickel and from about 8-15% w molybdenum and less than about 0.5% w phosphorus supported on a carrier consisting mostly of alumina; and separating the reaction product from said hydrotreating zone into a hydrogen-rich gas and a liquid hydrocarbon oil having reduced sulfur and/or heavy metal content.

Single-stage hydrotreating process

Conventional nickel or cobalt modified molybdenum disulfide-containing hydrotreating catalysts are generally prepared by impregnation. While this route has proven to be quite successful and has led to a variety of commercial products, inherent in the pore volume impregnation technique are several potential limitations. These limitations may be chemical or economic in nature. In order to overcome these potential limitations, we have developed a new, one-step route to the oxidic form of these nickel or cobalt modified molybdenum disulfide-containing hydrotreating catalysts. This route consists of reacting the metals solutions directly with a precipitated α-alumina monohydrate (boehmite) hydrogel prior to extrusion. The metals-containing hydrogel is extruded directly to pellet form and subsequently dried and calcined. Catalysts formed appear to have benefits not seen with conventional catalysts. As an example, the metals efficiencies and utilization of these catalysts can exceed conventional catalysts by 25%. Volumetric performances of these catalysts can also be quite good. Surface areas of the new, gel-derived catalysts are significantly higher than conventional catalysts. Crush strengths of the gel catalyst pellets can show improved strength over conventionally-prepared catalysts. Possible reasons for the enhancements in properties are discussed as well as details of the experimental procedures required to prepare these catalysts.

Hydrogel-derived catalysts. Laboratory results on nickel-molybdenum and cobalt-molybdenum hydrotreating catalysts

The invention relates to an improved method of presulfurizing a sulfidable metal or metal oxide-containing catalyst which minimizes sulfur stripping upon start-up of a reactor and improves catalyst activity. The method comprises contacting porous particles of the sulfidable catalyst with elemental sulfur at a temperature such that said elemental sulfur is incorporated in the pores of said catalyst by sublimation and/or melting and at the same time or subsequently heating the catalyst particles in the presence of a liquid olefinic hydrocarbon at a temperature greater than 150 °C.

A method of presulfurizing a catalyst

A process for preparing supported hydroconversion catalysts containing one each of Mo or W and of Co and/or Ni incorporated into a suitable support by preparing an aqueous impregnating solution having a pH in the range of 0.7-2.7 comprising mixing at least one each of a compound of molybdenum or tungsten and a compound of cobalt and/or nickel, a stabilizing amount of 0.2-1.0 mole of phosphorous per mole Mo or W, and from 2-6%w, basis support, of a suitable soluble amine compound. A suitable support is then impregnated with said solution followed by drying and calcining. The catalysts obtained demonstrate significantly increased hydrodenitrification activity.

Charles Terrell Adams

Papers

Process of hydrotreating and/or hydrocracking hydrocarbon streams or tail gas treating sulfur-containing gas streams

Single-stage hydrotreating process

Hydrogel-derived catalysts. Laboratory results on nickel-molybdenum and cobalt-molybdenum hydrotreating catalysts

A method of presulfurizing a catalyst

Process for preparing supported hydroconversion catalysts and catalysts thus prepared